Dominance of Prochlorococcus (Pro), Synechococcus (Syn) and picoeukaryotes (picoEuk) versus turbulent mixing, nutrient concentration and vertical flux of nutrients through turbulent diffusion.

Mouriño-Carballido B, Hojas E, Cermeño P, Chouciño P, Fernández-Castro B, Latasa M, Marañón E, Morán XAG, Vidal M


Nutrient supply controls picoplankton community structure during three contrasting seasons in the northwestern Mediterranean Sea


Picoplankton are the most abundant organisms in the ocean and often dominate planktonic biomass and primary production. Mouriño-Carballido and coauthors investigated, using observations of microturbulence, the influence of mixing and nutrient supply on picoplankton composition in the context of Margalef ?s mandala. Their results indicate that picophytoplankton groups exhibit contrasting responses to changes in nitrate supply, such that the ratio of prokaryotic to eukaryotic picophytoplankton biomass decreases with increasing nitrate supply. The role of nutrient supply in oligotrophic regions is made evident only when nitrate fluxes, and not just concentrations, are considered. Accurate estimates of nutrient supply are crucial to discern the role of environmental factors in controlling picophytoplankton community structure.


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